Problem: $ \left(\dfrac{27}{8}\right)^{-\frac{1}{3}}$
Answer: $= \left(\dfrac{8}{27}\right)^{\frac{1}{3}}$ Figure out what goes in the blank: $\Big(? \Big)^{3}=\dfrac{8}{27}$ Figure out what goes in the blank: $\Big({\dfrac{2}{3}}\Big)^{3}=\dfrac{8}{27}$ So $\left(\dfrac{27}{8}\right)^{-\frac{1}{3}}=\left(\dfrac{8}{27}\right)^{\frac{1}{3}}=\dfrac{2}{3}$